A couple of months ago I tooted looking for a vector grid-based editor. Nothing came up so we (Manufactura Independente) set out to make one.
It still has a set of kinks, but it's usable to the point that we've been using it to make a few designs.
We plan to release it in Feb/Mar under a free software copyleft license (AGPL). It runs on the browser with no server-side logic and no tracking.
If you'd like to try the beta and tell us about your experience, that'd be fab! Just reply to this toot and we'll get in touch.
@rlafuente have you seen dotgrid?
@grainloom Wow, I did not know this, looks like a fantastic tool. Thank you for this suggestion! I know what I'll be playing with tomorrow.
@grainloom @rlafuente Let me know if you need a hand with it ^^
@rlafuente Looks great. I'm definitely interested.
@rlafuente
i'd like to try it!
@rlafuente Looking good. I'd love to test it out, too :)
@rlafuente I'd like to try it!
@rlafuente i'd loooooooove to try it, looks awesome !
@rlafuente I'd like to try! 
@rlafuente It looks awesome! I'd like to try it and see what possibilities it has. Thanks!
@rlafuente hey I would also be interested in trying ;)
@rlafuente I’m interested!
@rlafuente i'd love to try it :D
@rlafuente i'd love to try it!